/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.runners.gaia.metrics;



import com.bff.gaia.metrics.Metric;

import com.bff.gaia.metrics.MetricConfig;

import com.bff.gaia.metrics.MetricGroup;

import com.bff.gaia.metrics.reporter.AbstractReporter;



import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.PrintStream;



/**

 * Gaia {@link com.bff.gaia.metrics.reporter.MetricReporter metrics reporter} for writing

 * metrics to a file specified via the "metrics.reporter.file.path" config key (assuming an alias of

 * "file" for this reporter in the "metrics.reporters" setting).

 */

public class FileReporter extends AbstractReporter {

  @Override

  public String filterCharacters(String input) {

    return input;

  }



  private String path;

  private PrintStream ps;



  @Override

  public void open(MetricConfig config) {

    synchronized (this) {

      if (path == null) {

        path = config.getString("path", null);

        log.info("Opening file: {}", path);

        if (path == null) {

          throw new IllegalStateException("FileReporter metrics config needs 'path' key");

        }

        try {

          FileOutputStream fos = new FileOutputStream(path);

          ps = new PrintStream(fos);

        } catch (FileNotFoundException e) {

          throw new IllegalStateException("FileReporter couldn't open file", e);

        }

      }

    }

  }



  @Override

  public void notifyOfRemovedMetric(Metric metric, String metricName, MetricGroup group) {

    final String name = group.getMetricIdentifier(metricName, this);

    super.notifyOfRemovedMetric(metric, metricName, group);

    synchronized (this) {

      ps.printf("%s: %s%n", name, Metrics.toString(metric));

    }

  }



  @Override

  public void close() {

    ps.close();

    log.info("wrote metrics to {}", path);

  }

}